154809979 has 4 divisors (see below), whose sum is σ = 157730976. Its totient is φ = 151888984.

The previous prime is 154809959. The next prime is 154809989. The reversal of 154809979 is 979908451.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979908451 = 19 ⋅51574129.

It is a cyclic number.

It is not a de Polignac number, because 154809979 - 2¹¹ = 154807931 is a prime.

It is a super-2 number, since 2×154809979² = 47932259195960882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (154809959) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1460419 + ... + 1460524.

It is an arithmetic number, because the mean of its divisors is an integer number (39432744).

Almost surely, 2^154809979 is an apocalyptic number.

154809979 is a deficient number, since it is larger than the sum of its proper divisors (2920997).

154809979 is an equidigital number, since it uses as much as digits as its factorization.

154809979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2920996.

The product of its (nonzero) digits is 816480, while the sum is 52.

The square root of 154809979 is about 12442.2658306275. The cubic root of 154809979 is about 536.9489332521.

The spelling of 154809979 in words is "one hundred fifty-four million, eight hundred nine thousand, nine hundred seventy-nine".